Did You Know...

... that centerpoint crossing is not in Block 5's way?

Current Block 5 (Opal - Opal)

posted Feb 4th, 2005 -
The NSL News reported yesterday that another change of the dive pool removed arrows and required degrees of turn in Block 5 (Opal - Opal). This change left some questions open concerning the centerpoint crossing of the vertical technique. The NSL News assumed that the pieces would still have to avoid the centerpoint crossing, even though the language indicates an open field for any technique.

The rules mention the centerpoint issue only related to a block where degrees of a turn are shown:

3.3. Performance Requirements

3.3.5. Where degrees are shown, (180°, 270°, 360°, 540°), this indicates the approximate degrees and direction of turn required to complete the inter as intended. The degrees shown are approximately that amount of the circumference of the subgroup’s centerpoint to be presented to the centerpoint(s) of the other subgroup(s).

Block 17 (Danish T - Murphy)

The NSL News still had doubts that the direct centerpoint crossing would be accepted by the judges - with or without required rotation. Past experiences with Block 17 (Danish T - Murphy) led to this wrong conclusion. The Block 17 situation had caused similar discussions in the past, and still sometimes is. The centerpoint crossing was the issue, even though the maneuver does not require a rotation.

Another small addition to the rules led to the assumption of the author that the judges are still eying the individual in Block 17. The committee added the definition of an individual's centerpoint to the rule book:

2.6. A subgroup’s centerpoint is one of the following:

1) The defined grip, or the geometric centre of the defined grips within a subgroup within linked jumpers.2) The geometric centre of an individual’s torso.

Fiona McEachern, Chair of the IPC Formation Skydiving Committee

This addition could also be related to Blocks 2, 3, 4, 20 and 22. However, these blocks have never caused any discussion of centerpoint issues, except John Eagle's Block 2 out the door. Thus, the NSL News assumed that the addition was related to Block 17. Then the centerpoint crossing would still be an issue for Block 17, and logically also for Block 5.

The NSL News was looking for clarification when a visitor at the NSL Discussion Forum brought up this topic after the story was posted. Another regular visitor of the NSL website was faster than the NSL News and had this clarification already on hand before the NSL News could even send the question.

Fyodor Mozgovoy with the Ladybirds in Croatia

Fyodor Mozgovoy is one of the organizers of the Malevsky Memorial Cup in Russia, and he also films the female national 4-way team of Russia, the Ladybirds, who won the bronze medal at the last World Meet in Croatia 2004. Mozgovoy contacted Fiona McEachern, the Chair of the IPC's Formation Skydiving Committee, when the question of Block 5 came up. McEachern made it very clear to Mozgovoy and the rest of the 4-way community that there are no limits for any technique when she was pointing to 3.3.5 of the IPC rule section:

Hello Fyodor,

This is exactly what we wanted. Cross vertical, forward, backward, cogginwise, without any regard to the centerpoint. Centrepoints only apply to degrees of turn:

3.3.5 Where degrees are shown, (180°, 270°, 360°, 540°), this indicates the approximate degrees and direction of turn required to complete the inter as intended. The degrees shown are approximately that amount of the circumference of the subgroup's centerpoint to be presented to the centerpoint(s) of the other subgroup(s).

Regards,Fiona

The NSL News sends thanks to Russia and to Australia for this clarification. Teams and competitors can begin training the shortest and quickest way to move from the first Opal to the second one. More details of the rule changes will follow.